Color image processing systems often include an input device (e.g., a scanner, copy machine, etc), an image manipulation device (e.g., a workstation), and one or more output devices (e.g., monitors, rendering devices, color print presses, etc.). Within such systems, consistency of color reproduction across system components is desirable. It is also desirable to attain similar consistency of color reproduction when image files are transferred between different color image processing systems.
In the printing of images on print media utilizing a rendering device, it is a common problem to emulate a color from a physical color patch supplied by, for example, a customer for print articles. The commercial rendering industry requires the capability of producing a spot color accurately and consistently in order to meet particular demands. Spot colors are specially mixed inks that can be applied by a printing press or other rendering device and are in contrast with overlayed CMYK (cyan, magenta, yellow, black) inks which can be applied by a process printing technique. Spot colors are typically characterized utilizing either CMYK or device independent colors such as, for example, those associated with the CIE L*a*b* Color Scale.
In common CMYK and RGB (red, green, blue) press emulation modes, an incoming image, graphics, and text object types for the data streams CMYK and RGB can be rendered such that the color values of an intermediate emulation press can be preserved to a target rendering device via color transformations. Such press emulation color preservation technique enables color consistent rendering to the target rendering device in a manner similar to that of the emulation press. In particular, when the target rendering device color gamut differs from the offset press color gamut, emulation enables similarity across the digital and offset rendering device in terms of visual color output. Conventionally, if a print shop that desires an offset emulation for an entire rendering job (e.g., a print job) via digital rendering, the color emulation can be achieved for RGB and CMYK workflows, but not for a spot color workflow. The spot colors, however, can be rendered only to the target rendering device with no ability to be preserved as if they were rendered to the offset press.
Based on the foregoing, it is believed that a need exists for an improved method and system for press emulation of spot colors in order to enable color matching across different data workflows and rendering workflows during a color offset complement digital rendering. A need also exists for appropriately mapping a target color in an ICC workflow to enable color preservation across the rendering device, as described in greater detail herein.